Catalyst removal workstations and systems incorporating same for tubular reactors

ABSTRACT

A system is used for removing catalyst from a tubular reactor vessel. A power box with a 110 volt to a 12 volt DC transformer is mounted outside the vessel and connected to a 110 volt power supply. An air manifold, also mounted outside the vessel, is connected to a high-pressure air supply and connects to several valves with a separate connection to the power box. Several workstations are placed on the tube sheet within the vessel. The workstation has a frame, a drum and reel assembly mounted on the frame along with a 12 volt DC motor. An air lance hose passes into the drum and reel assembly and, at the other end, connects to an air lance and vacuum assembly. A high pressure air hose connects the drum and reel assembly to one of the valves located outside of the vessel. A controller connects to the 12 volt DC motor to power the drum and reel assembly. The controller is also connected to the power box located outside the vessel and to a foot control. A seat is mounted on the drum and reel assembly.

BACKGROUND

[0001] The present invention relates to the field of catalyst reactorscontaining numerous reactor tubes within a vessel. For a generaldescription of such an environment and related technologies see U.S.Pat. Nos. 5,228,484, and 5,222,533 and the patents discussed therein.U.S. Pat. No. 5,228,484, in particular discloses a reel system forbreaking up and removing catalyst by a vacuum. This reel system isimplemented by placing the drum outside the reactor vessel. The lanceand nozzle are then run by a hose through a manway into the reactorvessel to a worker. There is also a line running to a control box foreach worker. The workers inside the vessel normally sit on a plasticbucket when performing catalyst unloading operations within the vessel.As there may be several workers within the vessel unloading the catalystfrom the tubes, there are numerous hoses and lines running into thereactor. If the hoses and/or lines become tangled the workers inside thevessel need to communicate the circumstances to workers located outsidethe vessel.

[0002] The control boxes used in the prior systems received a 110 voltpower supply. For purposes of safety, it may not be desirable to have a110 volt power supply located within a reactor vessel.

[0003] The reactor vessels have an opening or manway which can be ofdifferent sizes. However the opening is round. The manway may be at thetop or on the side of the reactor vessel above the tube sheet. Thelargest manway to a reactor vessel of which the applicant is aware has adiameter of approximately thirty-six inches, and the manways to tubularreactor vessels have an opening ranging from a twenty to a thirty-sixinch diameter. In some instances the reactor vessel has a flanged,removeable head around the perimeter of the reactor vessel itself (inwhich case the head of the vessel is removed to form the manway).

[0004] The prior reel systems have been made with a square outer casingwhich further suggests that such reel systems were not designed forimplementation within the reactor vessel. Moreover, after the hose isreeled into a square or large casing, the stiffness of the hose (e.g. aplastic hose) causes the hose to spring back and expand away from thereel. In a square casing there is more room for the hose to spring backwhich leads to tangling of the hose on the reel.

SUMMARY

[0005] The present system, apparatus and methodology increase theefficiency of catalyst unloading operations in tubular reactor vesselsby reducing worker fatigue, tripping hazards, electrical hazards andloss of operational time due to tangling of hoses.

[0006] A system is disclosed for removing catalyst from a tubularreactor vessel. A power box with a 110 volt to a 12 volt DC transformeris mounted outside the vessel and connected to a 110 volt power supply.An air manifold, also mounted outside the vessel, is connected to ahigh-pressure air supply and connects to several valves with a separateconnection to the power box. Several workstations are placed on the tubesheet within the vessel. The workstation has a frame, a drum and reelassembly mounted on the frame along with a 12 volt DC motor. An airlance hose passes into the drum and reel assembly and, at the other end,connects to an air lance and vacuum assembly. A high pressure air hoseconnects the drum and reel assembly to one of the valves located outsideof the vessel. A controller connects to the 12 volt DC motor to powerthe drum and reel assembly. The controller is also connected to thepower box located outside the vessel and to a foot control. A paddedswiveling seat is mounted on the drum and reel assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 represents an elevational schematic of a reactor vessel andthe working system of the invention.

[0008]FIG. 2 is a perspective view of the workstation partially incross-section.

[0009]FIG. 3 is an elevational sectional view of the seat and swivelassembly.

DETAILED DESCRIPTION

[0010]FIG. 1 represents a catalyst reactor vessel 10 with workers 12performing a catalyst unloading operation. The vessel 10 has a manway 14forming an opening to a tube sheet 15 which is a substantially flatperforated surface located at the upper end of numerous reactor tubes16. The tubes contain catalyst to be removed by high-pressure air and avacuum as known to one of ordinary skill in the art. The tubes 16 mayhave an inner diameter ranging from ¾ of an inch up to two inches andmay be up to sixty feet long from top to bottom.

[0011] The workers 12 unloading the catalyst may be seated on thecatalyst removal workstation 20. Outside the vessel 10 a 110 volt ACpower supply 22, for example (although other voltages may be used), isconnected by a line 24 to a power box 26 with a transformer 27 a and analternating current to a direct current converter circuit 27 b, forexample, a power box 26 which converts 110 volt AC to 12 volt DC. A lowvoltage DC line 28, which in the illustrated embodiment is 12 volts dc,runs from the power box 26 to the workstation 20. A high-pressure airsupply 30, for example, at 300 psi is connected by a line 32 to an airmanifold 34. The air manifold 34 has several connectors 36 for making aconnection to a valve 38 such as a solenoid valve. The solenoid 38 isnormally closed (and would not be operational with 12 volt DC power) andis connected by a 110 volt line 40 (although other voltages may be used)to the power box 26. A high pressure air hose 42 runs from the valve 38through the manway 14 to the workstation 20. A vacuum source 44 isconnected by a vacuum line 46 to a catalyst collection manifold 48 asknown to one of ordinary skill in the art.

[0012] The line 28, hose 42 and hose 46 must all run through the manway14 into the vessel 10 to support a single workstation 20. During normalcatalyst unloading operations there are normally five to tenworkstations 20 per reactor vessel 10 when performing catalyst unloadingoperations. Also, the five to ten workers may be working up to twelve tofourteen hours at a workstation 20 during catalyst unloading operations.

[0013] Referring to FIG. 2 the ergonomic catalyst removal workstation 20is shown. The workstation 20 is of a unitary construction and generallyincludes a drum and reel assembly 50, an air lance and vacuum assembly60, a seat 70, and a control assembly 80.

[0014] The drum and reel assembly 50 has a hollow drum 52 which enclosesa high-pressure hose reel (not shown) as known to one of ordinary skillin the art. The drum 52 has a hose guide or opening 53 through thesidewall of the drum 52 which may be about three inches by ten incheswide to assist in guiding the hose into and out of the drum 52. The drum52 is mounted on a frame 56. The lower surface 57 of the frame 56 isadapted for maintaining stability on the tube sheet 15 in the vessel 10,e.g. a flat plate, as shown. Arcuate handles 58 which generallycorrespond to the curvature of the drum 52 are attached to the frame 56.The handles 58 may be used for carrying or moving the workstation 20.The air lance and vacuum assembly 60 includes a high-pressure air lancehose 62 which runs into the drum 52, raps around the reel and isconnected to the high pressure air line 42 as known to one of ordinaryskill in the art. The other end of the air lance hose 62 connectsthrough the catalyst collection manifold 48 to a lance 64 and nozzle 66.The nozzle 66 has forward jets to fluidize the catalyst and backwardjets to move the catalyst out of the tube 16. The catalyst collectionmanifold 48 is connected to a vacuum hose 46 for removing catalyst fromthe tube 16. The lance 64 may be moved up and down through a hole in thecatalyst collection manifold 48.

[0015] The seat 70 is mounted on the drum 52 preferably through a swivelconnection 100 (see FIG. 3). The swivel connection 100 includes a topplate 102 and a bottom plate 104 each defining a race for containingball bearings 106. A rivet 108 holds the top plate 102 and the bottomplate 104 together. The top plate 102 is attached to the seat 70 and thebottom plate 104 is connected to the drum 52. Therefore a worker 12 mayrotate to other tubes while sitting on the seat 70. The seat 70preferably includes a padded cover 72 for reducing worker fatigue.

[0016] The control assembly 80 generally includes a controller box 82, alow voltage dc motor 84, which in the illustrated embodiment is a 12volt dc motor, and a foot control 90. The low voltage line 28 runsthrough the manway 14 and connects to the controller box 82. Thecontroller box 82 may be mounted on the frame 66. The low voltage motor84 may also be mounted on the frame 66. Low voltage such as 12 volt dcpower lines 85 run from the controller box 82 to the low voltage motor84. The low voltage motor 84 is used to reel up the air lance hose 62into the drum and reel assembly 50 by, e.g. a belt drive pulley or agear to gear system. Note, the air lance hose 62 is normally hand pulledfor extending same into and down a tube 16. A low voltage power cable86, which in the illustrated embodiment is a 12 volts dc power cable,runs from the controller box 82 to the foot control 90. The foot control90 has a box shaped enclosure 92 with walls on five sides (open on oneside). Foot pads 93 and 94 are mounted in the enclosure 92. Theenclosure 92 also houses two levers, an air lever 96 and a motor reellever 98. If the worker depresses the air lever 96 the normally closedvalve 38 will be opened to direct air at, e.g. 300 psi, to the lance. Ifthe worker 12 depresses the motor reel lever 98, then the motor 84 isactivated to reel up or in the high-pressure air hose 62. A safety-wall99 is attached to the enclosure 92 between the air lever 96 and themotor reel lever 98. The safety-wall 99 extends to a height above thelevers 96 and 98 but not from the bottom wall to the top wall of theenclosure 92. As such, a worker may simply move his or her foot from onelever to the other lever 96 or 98 without removing their foot from theenclosure 92. However the safety-wall 99 functions as a divider betweenthe levers 96 and 98. This prevents the worker's foot from accidentallyslipping from one lever to the other lever 96 or 98, and preventsactivation of the reel and the air at the same time.

[0017] It is critical for an outer diameter of at least one crosssection of the workstation 20 to be less than the inner diameter of themanway 14 for placing the workstation 20 within the vessel. For example,a vertical cross section taken through the seat 70, the drum and reelassembly 50 and the frame 56 perpendicular to the winding axis of thedrum and reel assembly 50 (or through the arcuate handle 58 and frame56) should have a diameter less that twenty inches (if necessary, theseat can be removed).

[0018] As there is no air motor placed in the vessel 10, no air motorlubricating oils will enter the manway 14. Such oils can kill orcontaminate the activate of the catalyst.

[0019] While a foot control 90 has been illustrated and described, othertypes of controls, for example a hand control, could be used. Variouscommunications lines, such as between the foot control 90 and the valves38 and controller 82, could be established with a radio frequencytransmitter and receiver so as to replace various lines, such as powercable 86. Battery power having sufficient power to energize variouscomponents of the system may also be implemented.

[0020] In conclusion, therefore, it is seen that the present inventionand the embodiments disclosed herein are well adapted to carry out theobjectives and obtain the ends set forth. Certain changes can be made inthe subject matter without departing from the spirit and the scope ofthis invention. It is realized that changes are possible within thescope of this invention and it is further intended that each element orstep recited is to be understood as referring to all equivalent elementsor steps. The description is intended to cover the invention as broadlyas legally possible in whatever form it may be utilized.

What is claimed is:
 1. An apparatus for removing catalyst from a tubular reactor, comprising: a frame having a lower surface adapted for stability when mounted on a tube sheet; a drum and reel assembly mounted on the frame and having a hose guide opening; an air lance hose at one end passing through the hose guide opening and connecting inside said drum and reel assembly and at the other end connecting to an air lance and vacuum assembly; a low voltage motor mounted on the frame and connected to said drum and reel assembly; a controller connected to said low voltage motor; a control including an air lever and a lever for activating said low voltage motor connected to the controller; and a seat mounted on said drum and reel assembly.
 2. The apparatus according to claim 1, further including a swivel connector for mounting said seat to said reel and drum assembly.
 3. The apparatus according to claim 1, further including a padded covering mounted over said seat.
 4. The apparatus according to claim 1, wherein a diameter of a cross section taken through said seat, said reel and drum assembly and the frame is less than twenty inches.
 5. The apparatus according to claim 1, wherein said control includes a safety wall extending to a height above a height of the air lever and the lever for activating said low voltage motor.
 6. The apparatus according to claim 1, wherein said control is a foot control.
 7. The apparatus according to claim 1, wherein said low voltage motor is a 12 volt dc motor.
 8. A system for removing a catalyst from a reactor vessel, the reactor vessel having a tube sheet mounted within the vessel at an upper end of a plurality of vertical reactor tubes also mounted within the vessel, and a manway for accessing the tube sheet defining an opening to the vessel, comprising: a power box with a transformer for transforming to a low voltage mounted outside the vessel and connected to a power supply; an air manifold mounted outside the vessel and connected to a high-pressure air supply, said air manifold having a plurality of connectors to a corresponding plurality of valves mounted outside the vessel wherein said valves are connected to said power box by a line; and a workstation placed on the tube sheet, wherein said workstation includes: a frame having a lower surface adapted for stability when mounted on the tube sheet; a drum and reel assembly mounted on the frame and having a hose guide opening; an air lance hose at one end passing through the hose guide opening and connecting inside said drum and reel assembly and at the other end connecting to an air lance and vacuum assembly; a high pressure air hose connecting said drum and reel assembly to one of said valves; a low voltage motor mounted on the frame and connected to said drum and reel assembly; a controller connected to said low voltage motor and connected by a communications line to said power box; a control including an air lever and a lever for activating said low voltage motor connected to the controller; and a seat mounted on said drum and reel assembly.
 9. The system according to claim 8, further including a swivel connector for mounting said seat to said reel and drum assembly.
 10. The system according to claim 8, further including a padded covering mounted over said seat.
 11. The system according to claim 8, wherein said control includes a safety wall extending to a height above a height of the air lever and the lever for activating said low voltage motor
 12. The system according to claim 8, wherein said control is a foot control.
 13. The system according to claim 8, wherein said low voltage motor is a 12 volt dc motor.
 14. The system according to claim 8, wherein a diameter of a cross section taken through said seat, said reel and drum assembly and the frame is less than twenty inches.
 15. A method for removing a catalyst from a reactor vessel wherein the reactor vessel has a tube sheet mounted within the vessel at an upper end of a plurality of vertical reactor tubes also mounted within the vessel, and a manway above the tube sheet defining an opening to the vessel, comprising the steps of: placing a workstation having a drum and reel assembly and a worker control assembly inside of the vessel on the tube sheet; and operating the workstation for removing the catalyst. 